Currently, there is an electrical connector for improving signal transmission quality, such as that in Chinese patent application No. CN200420029031.1. The electrical connector includes a plastic body 10, and an upper terminal row 20a and a lower terminal row 20b disposed in the plastic body 10. A first grounding sheet embedding cavity 12a is disposed on the plastic body 10 and is located above the first terminal row 20a and adjacent to the first terminal row 20a. A second grounding sheet embedding cavity 12b is disposed on the plastic body 10 and is located above the second terminal row 20b and adjacent to the second terminal row 20b. A first grounding sheet 40a and a second grounding sheet 40b are respectively embedded into the upper and lower embedding cavities 12a and 12b, and separately conducted to a shielding casing 30 by using a joining tongue 42, so as to conduct electromagnetic waves generated by the first and second terminal rows 20a and 20b to a grounding circuit, thereby avoiding interference from the electromagnetic waves of the first and second terminal rows 20a and 20b. 
This structure requires sufficient thickness of the plastic body, such that the grounding sheets can be embedded into the embedding cavities of the plastic body. However, this is contrary to the ultrathin-type development trend of the electrical connector, and this electrical connector cannot take account of both thinness and signal transmission quality.
Therefore, a heretofore unaddressed need exists in the art to address the aforementioned deficiencies and inadequacies.